Office chair



FIG. 1 is a front view of an office chair showing my new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a right side view thereof;

FIG. 4 is a back view thereof;

FIG. 5 is an bottom view thereof;

FIG. 6 is a sectional end view along line A—A of FIG. 1 thereof; and,

FIG. 7 is a front view showing an amplifier accessory installed thereon.

The broken lines shown in FIG. 7 are for environmental structure only and form no part of the claimed design. 

The ornamental design for an office chair, as shown and described. 